Artemisia annua

Artemisia annua (Quing-hao), a fern-like weed, has been used in Chinese medicine for more than 2000 years in the treatment of fever. The active principle, artemisinin (quinghaosu, QHS, artenuin), a sesquiterpene lactone with a characteristic peroxide bridge, was isolated by Chinese scientists in 1972 from the leafy portion of the plants (). Assays carried out on other species of Artemisia failed to show any appreciable amount of artemisinin (TDR 1981). However, other species of the genus are considered important as a source of medicines and flavors. From Artemisia douglasiana, for example was isolated dehydroleucodin (DHL), a sesquiterpene lactone with antiulcerous properties (). Artemisia dracunculus, also known as tarragon, is used as a spice in cooking and to flavor vinegar, and Artemisia absintium used in the production of volatile oils (). Botanical Description Artemisia annua (), popularly known as sweet Annie, annual wormwood, or sweet wormwood is a member of the Compositae family (Asteraceae). It is an annual herbaceous plant that grows in wild forms in different parts of the world, exhibiting great variety in both shape and size. It ranges from small, almost prostrate plants to tall, erect specimens which Read more […]

Cultivation of Artemisia

The genus Artemisia includes a large number of species and some have been cultivated as commercial crops with a wide diversity of uses. Some better known examples include antimalarial (Artemisia annua – annual or sweet wormwood), culinary spices (Artemisia dracunculus – French tarragon), liquor flavouring (Artemisia absinthium – absinthe), garden ornamental (A. abrotanum – southernwood) and insect repellent (Artemisia vulgaris – mugwort). However this review will concentrate on the cultivation of Artemisia annua because of its contemporary importance as a source of new and effective antimalarial drugs. During World War II and in the years immediately following, the world wide incidence of malaria was dramatically reduced. On the one hand the Anopheles mosquito vector was successfully controlled by the advent of the insecticide DDT and on the other the organisms causing human malaria – the single celled Plasmodium species: falciparum, vivax, malariae and ovale – were effectively controlled by the use of synthetic derivatives of quinine. The specific statistics for India illustrate this dramatic reduction. In 1961 the incidence of malaria had fallen to about 100,000 reported cases, however by 1977 the number of reported Read more […]

Artemisia: Plant Cultural Techniques

Plant Establishment Natural stands In China Artemisia annua traditionally has been harvested from wild natural self seeded stands. Although no specific crop production statistics are available, because of a confidentiality policy of Chinese authorities, it is believed that the bulk of Chinese production still comes from wild stands. These stands are the source of much of the artemisinin derived drugs used in China and probably the bulk of those drugs exported elsewhere (WHO, 1994) although some selected lines of Artemisia annua are cultivated as a row crop in Szechwan Province (). Ideally the harvesting of raw material for medicinal drug production from wild stands is not a good policy (). The plant material in wild stands is typically very variable in its content of the required medicinal constituents and this has an impact on the economics of drug extraction. Added to this the continual encroachment and elimination of wild stands will ultimately limit the source of genetic variability which is vital to the development of improved seed lines (). Another negative factor against utilisation of wild stands is that transport distances often become uneconomic with a crop such as Artemisia annua with a relatively low artemisinin Read more […]

Ptelea trifoliata (Quinine Tree, Hop Tree)

Ptelea trifoliata L. (Rutaceae) is a bush of North American origin that has been cultivated in Europe since the eighteenth century. Pharmacological properties (particularly bacteriocidal and cytotoxic activities) are due to the presence of coumarins and quinoline alkaloids. Botany and Distribution Ptelea trifoliata’s common names include: quinine tree, potato chip tree, and hop tree (the latter being the most widely used today); in Spanish, Cola de Zorillo; in French Ptelea a 3 feuilles, trefle de Virginie, Orme de Samarie – this last name was first used in France around 1800 and is still widely used (). Ptelea trifoliata L., described by Linnaeus in 1753, is extremely variable in its morphology and chemical composition. This explains the description of numerous varieties which have often been raised to the rank of species. The most recent revision of the genus Ptelea is by Bailey () who recognizes only three species: Ptelea trifoliata L., Ptelea crenulata Greene, and Ptelea aptera Parry, although he subdivides P. trifoliata into five subspecies and ten varieties. The Ptelea species are deciduous bushes, 3-4 m tall, with trifoliate aromatic leaves (). A large number of detailed descriptions exist (). There have Read more […]

Citrus in Traditional Medicine

Citrus in traditional Asiatic medicine In a comparative study of the use of herbal drugs in the traditional medicines of India and Europe, Pun () found a marked similarity between the drugs used in the two continents. He attributed this not only to the similarity of the vegetation in the two areas, but also to the influence that traditional Indian medicine, in particular the Atherveda, one of the most ancient repositories of human knowledge, had on Egypt, Greece and Rome. He listed the principal uses of a small number of these drugs, including bitter orange peel, which in India is used as an aromatic, stomachic, tonic, astringent and carminative agent, and lemon, which is used as a flavouring and for its carminative and stomachic effects. In the Valmiki-Ramayana, written after the Vedas and one of the most sacred of all religious books which enumerates the virtues of the medicinal plants that Lord Rama (Vishnu) met during his fourteen-year journey around different parts of India, Karnick and Hocking () identified and listed fifty of these drugs with their use as described in the Ayurvedica (or native Indian) system of medicine. The immature fruit of Citrus aurantifolia (Christm) Swingle was used as an fortifier, Read more […]

Artemisia Species in Traditional Chinese Medicine and the Discovery of Artemisinin

Qing hao-an antimalarial herb A herb, named Qing Hao (usually pronounced ching how) in Chinese, sweet Annie or sweet wormwood in English, and properly known as Artemisia annua L. has become well known in western countries during the last 20 years. Herbal companies, which deal with traditional Chinese medicine (TCM), receive several inquiries concerning this herb every day. A. question commonly asked by those about to travel to Africa or S.E. Asia is “Can I take the herb called Qing Hao to prevent malaria during my trip?” Unfortunately, the answer has disappointed many people because although this herb is used for the treatment of malaria in TCM, usually combined with other herbs, it is not recommended for the prevention of the disease or as a deterrent to mosquitoes. However, the leaves of Qing Hao were burned as a fumigant insecticide to kill mosquitoes in ancient China but this practice no longer continues today since the development and marketing of more efficient mosquito-repellant devices. The discovery of artemisinin Qing Hao is a herb commonly used in China with a long history of use as an antipyretic to treat the alternate chill and fever symptoms of malaria and other “heat syndromes” in the traditional Chinese Read more […]

Artemisia Annua in Chinese Traditional Medicine

Yeung (), in a short monograph on Qing Hao gives A. apiacea Hance as a synonym for Artemisia annua and describes the taste and property of the herb as bitter, pungent and cold. Its functions are antimalarial, to reduce the heat caused by deficiency of Yin, and to clear the summer heat. The medicinal uses of Qing Hao are given as malaria, febrile diseases, tidal fever, low grade fever and summer heat stroke. Although Qing Hao may be used as a cooling herb for the relief of symptoms, traditional chinese medicine places great emphasis on treating the underlying cause of an illness and as explained above, diagnosis is often much more precise than it is in western medicine. This helps to explain why complex combinations of Chinese herbs are used; additional herbs (which may be referred to as “minister”, ” assistant” or “guide” herbs are added to the principal (or “emperor” herb) in order to complement or modify its action so that the traditional chinese medicine prescription is tailored for the needs of the individual patient. An example of a prescription for the treatment of malaria using traditional chinese medicine is the classical formula Qing Hao Bie Jia Tang (decoction of Carapax Trionycis and Qing Hao) which is Read more […]

Traditional Uses of Neem

The therapeutic efficacy of neem must have been known to man since antiquity as a result of constant experimentation with nature. Ancient man observed the unique features of this tree: a bitter taste, non-poisonous to man, but deleterious to lower forms of life. This might have resulted in its use as a medicine in various cultures, particularly in the Indian subcontinent and later on in other parts of the world. Ayurveda The word neem is derived from Sanskrit Nimba, which means “to bestow health”; the various Sanskrit synonyms of neem signify the pharmacological and therapeutic effects of the tree. It has been nicknamed Neta — a leader of medicinal plants, Pichumarda — antileprotic, Ravisambba — sun ray-like effects in providing health, Arishta — resistant to insects, Sbeetal — cooling (cools the human system by giving relief in diseases caused by hotness, such as skin diseases and fevers), and Krimighana — anthelmintic. It was considered light in digestion, hot in effect, cold in property. In earlier times, patients with incurable diseases were advised to make neem their way of life. They were to spend most of the day under the shade of this tree. They were to drink infusions of various parts of Read more […]

Stephania

Importance and Distribution of the Genus The genus Stephania (Menispermaceae) comprises approximately 50 species distributed from Africa through Asia to Australia. The importance of the genus in traditional medicine in Asia and Africa is well documented. The underground tubers of the vines are generally characterized by powerful pharmacological effects. Stephania abyssinica is a creeper indigenous to southern and eastern Africa. The leaves of this plant are used as a purgative and emetic, whereas the roots are employed in the treatment of roundworm, menorrhagia and boils. Stephania bancroftii is used by the aboriginal communities of Australia both as a treatment for diarrhea and as a fish poison. Stephania cepharantha (), a perennial plant native to mainland China known by the vernacular name “bei-yan-zi”, is commonly used as a folk medicinal herb. Decoctions from the tuber of Stephania cepharantha are traditionally used in China to treat a number of diseases including parotiditis, gastric ulcer, leukopenia, alopecia areata and alopecia androgenetica. The major components of this crude drug, known as Cepharanthin preparations, are the bisbenzylisoquinoline (BBI) alkaloids cepharanthine, isotetrandrine and cycleanine. Stephania Read more […]

Artemisia annua L.

Malaria, one of the oldest known diseases, was referred to in Egyptian writings of the 16th century B.C. In the 17th century, Italians believed that breathing bad air (mal aria) arising from swamps was responsible for the disease, and the term malaria first entered the English medical literature in the first half of the 19th century. Each year, this disease afflicts over 300 million people worldwide, killing up to 2.7 million, mostly children. Most of these cases occur in Africa, but large areas of Asia, Central, and South America have high incidences of the disease. Out of 37 countries and territories, which are members of the Pan American Health Organization (PAHO), World Health Organization (WHO), 21 still have active malaria transmission (PAHO/WHO 1998). Malaria has been treated for over 40 years with quinine-derived drugs. However, Plasmodium falciparum has developed resistance against these drugs in several areas of the world. Artemisinin (qinghaosu) (), a sesquiterpene lactone belonging to the cadinane series, is an antimalarial compound first isolated from Artemisia annua L. by Chinese scientists in 1972. In addition to a lactone group, artemisinin contains an endoperoxide bridge, which is rarely found in Read more […]